Cover full CRUD lifecycle (create → list → update → delete → verify gone) and the reply path where parent_id populates replyTo on the new comment. Tests run against the live mcp container via the existing nc_mcp_client fixture and reuse the temporary_board_with_card fixture for setup/cleanup. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>